The auctex-package in Debian unstable seems to have recently started to depend on emacs23.
I have emacs-snapshot (GNU Emacs 24) installed and no need for emacs23. So, with the aid of Google, I learned to type:
$ equivs-control fake-emacs23 $ jove fake-emacs23 $ equivs-build fake-emacs23 $ sudo dpkg --install fake-emacs23_1.0_all.deb
And then I could install auctex again. Nice!
The fake-emacs23 control file looked like this:
Section: misc Priority: optional Standards-Version: 3.9.2
Package: fake-emacs23 Provides: emacs23 Architecture: all Description: Fake Emacs 23 pretends to provide Emacs 23 so auctex can be installed. Fake package providing emacs23.
Simple as that.